1. Field of the Invention
The present invention relates to a method of assembling a disk recording apparatus and an assembling apparatus for the same.
2. Description of the Related Art
A wide variety of modern computers, such as personal computers, desktop computers, notebook-type computers, etc., use disk recording apparatuses as memories for storing a great deal of information.
A disk recording apparatus, e.g., a magnetic disk drive, generally comprises a plurality of magnetic disks arranged in layers, magnetic head assemblies, and a head actuator. Each of the magnetic head assembly includes a magnetic head for recording on and reproducing information from the magnetic disk. The head actuator supports the magnetic head assemblies for movement relative to the magnetic disks and serves to move them to desired tracks on the disks.
The magnetic disks are fitted on the cylindrical hub of a spindle motor and are supported coaxially with one another and in spaced layers. The magnetic disks are rotated at a given speed by driving the spindle motor. The spindle motor, head actuator, etc., are mounted on a base.
The spindle motor has the hub that serves as a rotor, and a flange is formed on one end side of the hub. The magnetic disks are fitted on the hub and sandwiched between the flange of the hub and a damper that is screwed to the upper end of the hub.
Since a rotating part that includes the hub of the spindle motor, clamper, and magnetic disks rotates at high speed, its center of gravity must be coincident with the center of rotation. If the center of gravity of the rotating part and the center of rotation are not coincident, vibration is caused during the rotation, so that the data write/read accuracy for the magnetic disks inevitably drops.
In a notebook-type computer, moreover, a magnetic disk drive is often located under a keyboard or palm rest, so that the vibration of the disk drive may be transmitted directly to a user's body in some cases.
Usually, the non-coincidence of the center of gravity of the rotating part and the center of rotation is removed during the assembly of the magnetic disk drive. Described in Jpn. Pat. Appln. KOKAI Publication No. 6-342578, for example, is an assembly method for a magnetic disk drive in which a weight for adjustment is placed on a damper for magnetic disks. In this case, however, the eccentricity is measured by means of a measuring device separate from the adjusting device.
Further, a correcting mechanism for dislocation of disks is described in Jpn. Pat. Appln. KOKAI Publication No. 6-302099. In this correcting mechanism, servo position information that is written on a recording medium is used for the measurement of eccentricity, and the disks themselves are moved to adjust the eccentricity.
Described in Jpn. Pat. Appln. KOKAI Publication No. 2000-268533, furthermore, is a method in which each disk is moved and centered by means of four actuators.
However, the conventional methods of assembly and adjustment described above require independent adjusting and measuring devices or a large number of actuators, so that the adjusting operation is troublesome, and the whole equipment is inevitably large-scaled.